An antenna which is continuously rotating may result in RF interferences to another rotating antenna operating in the same RF band, when the antennas are illuminating each other. Existing solutions to prevent interferences are based on electromagnetic diversity in the temporal domain, in the spatial domain or in the frequency domain.
In the temporal domain, these solutions propose blanking periods, by switching off the system when its antenna points in the fixed directions of other antennas. However, a major disadvantage of blanking periods is that the system does not provide an overall coverage: data may be missed during the time the radar system is blanked.
In the spatial domain, these solutions propose blanking sectors, by switching off the system when its antenna points in the fixed directions of other antennas. However, a major disadvantage of blanking sectors is that the system does not provide an overall coverage: data may be missed in blanked sectors.
In the frequency domain, these solutions propose using a different frequency for each system on transmits and using filtering means on receive, so as to make interferences impossible. However, a first disadvantage is that the filtering means may not be efficient or involve high cost. Yet another major disadvantage of using different frequencies is that you cannot mix all the systems you want. Especially on a ship, some systems are required, which must operate in the same RF band.